Take (1) large graham cracker and break it in half (one for top cracker and one for bottom cracker).
Place chocolate on one of the crackers.
Roast your marshmallow on a stick until golden brown and starting to get squishy.
Sandwich the marshmallow between the chocolate and the graham crackers press a little, then they are ready to eat.

You can also make S'mores in the Microwave:

Take the same ingredients as above for the campfire s'mores.

Take (1) large graham cracker and break it in half (one for top cracker and one for bottom cracker). Place one graham cracker on a plate and top it with a large marshmallow.
Put in the microwave on High for 10 to 12 seconds until it starts melting.
Top the hot marshmallow with a square of chocolate and then with the remaining graham cracker part.
Squeeze down until the marshmallow begins to puff out of the sides of the s'more. Then it is ready to eat.

*Alternatively you can place both the marshmallow and chocolate together and microwave until the marshmallow becomes squishy.